Heat is deadly. Across the world, global warming contributed to nearly 300,000 deaths among people older than 65 in 2018 and billions of lost work hours.
And without serious action to mitigate climate change, its disastrous effects will have increasingly serious implications for public health, The Lancet Countdown on Health and Climate Change’s latest annual report found.
The report is a product of intense collaboration among 120 experts worldwide, including climate scientists, economists, political scientists, epidemiologists and doctors. Yale researchers played a pivotal role: Yale School of Public Health professors Robert Dubrow, Jodi Sherman and Matthew Eckelman are among the co-authors of the study.
For the report, Sherman and Eckelman’s team investigated to what extent the health care sector contributes to global carbon emissions. They found that this part of the economy was responsible for nearly one-twentieth of all emissions in 2017 — though some parts of the world were bigger polluters than others. Data shows that the United States emitted more than 1,700 kilograms of carbon dioxide per person that year from the health care sector, while China contributed just less than 500 per person.
The team also found that rising health care-related emissions happen where health care access and quality is improving — but only up to a point. After a country reaches 400 kilograms per person, additional emissions do not correlate with health system improvements. In developed countries like the United States, these results suggest that health care could maintain quality while still significantly lowering its pollution output.
But as heat and other climate change-related effects continue to pose threats to vulnerable populations, these emissions numbers could still grow.
Sherman added that the vast majority of these emissions are from the supply chain — the part of the health care sector that produces, distributes and eventually disposes of medical tools, drugs and protective gear. Since many devices are only designed for one use, the sheer amount of disposable products that are used to support patient care can lead to higher emissions. But this could be on the mend, she said. “What the COVID-19 pandemic has elicited is our overdependence on disposable goods,” she said. “Relying more on reusable goods … is an opportunity to reduce emissions and improve supply-chain resiliency.”
Supply-chain emissions are also closely tied to the ways in which each country uses energy, especially for electricity. “Transitioning to renewable sources of electricity, both directly by hospitals and clinics as well as by health care suppliers such as drug-makers, is one of the most effective ways to reduce health care emissions,” Eckelman noted.
Dubrow looked into the impact of air conditioning on global emissions and climate change. What his team found was startling: Indoor cooling accounts for nearly 9 percent of total worldwide electricity use — and this share could rise. Indeed, the resulting air pollution from increased cooling could kill around 1,000 additional people every summer in the eastern United States by 2050.
“People deserve and need good indoor cooling, so the issue is: How do you do that in a sustainable way?” he said. “I, unfortunately, don’t have all of the solutions to that, but this identifies it as a very important problem that needs to be addressed.”
The report marks the fifth time The Lancet has published its annual roundup of climate research. But this one has special significance: It was published on the anniversary of the Paris Agreement, a global pact meant to fight climate change and reduce carbon emissions, from which the United States withdrew in November.
For the researchers, working on such a large study was an invigorating experience.
“I actually find it inspiring to work with people from all around the world on a common purpose that is something that I really believe in,” Dubrow explained. “I have nothing but positive things to say about being part of this collaboration.”